Stainless steel wire after rolling, the surface of the oxide and the collective combination of solid, difficult to remove, if the direct pickling, the effect is not very good, so you can first carry out a pretreatment measures, and then the use of oxidizing agents, activators of mixed acid cleaning in order to more effective removal of stainless steel oxide.
Stainless steel wire commonly used pretreatment methods are two: alkali dip method and shot blasting method.
1、Alkali dip method
Alkali dip is the wire immersed in alkaline molten salt or solution to change the structure of the oxide skin. Alkali dip can be divided into molten salt alkali dip and solution alkali dip.
Stainless steel by molten salt alkali dip surface is not damaged, pickling metal loss is relatively small, and can greatly shorten the pickling time, improve production efficiency, but the molten salt to maintain a high temperature state, high energy consumption, molten salt alkali dip another disadvantage is the need to set up a special alkali tank, alkali tank heating cycle is long, high energy consumption. Some manufacturers who do not have a large output and cannot produce continuously choose the solution alkali leaching process.
Solution alkali leaching principle and molten salt alkali leaching the same, but the use of temperature below the boiling point of the solution, alkali leaching time correspondingly long. With alkaline potassium permanganate aqueous solution (temperature of about 100 ℃) soak despite the energy savings, but low production efficiency, only as a supplementary means.
2、Blasting method
Shot blasting method is used to throw nine machine will be accelerated to a certain speed, and then sprayed at an angle to the surface of the rotating wire, in the impact of the pellet, the surface of the steel produced elastic deformation, oxidation almost no elastic deformation capacity, so the oxide broken, loose, off. General carbon steel and low alloy steel wire oxidation is thicker, and weaker bond with the matrix with the shot peening method can remove the oxidation, but stainless steel wire oxidation thin, dense, and strong bond with the matrix, it is difficult to use the shot peening method to remove the oxidation, can only be used as a pretreatment means before pickling annealed martensitic steel, ferritic steel and does not allow alkali immersion of precipitation hardening stainless steel wire pretreatment. The pellets are made of steel with a certain hardness and are resistant to cracking. The material, diameter, blast speed and volume of the shot will affect the surface of the wire to be cleaned. The shot blasting method is divided into single unfolded shot blasting and coil blasting treatment, considering the production efficiency, the scale of production is appropriate to use the coil blasting machine.
Advantages of the blasting method: high efficiency, energy saving, small footprint, no pollution of the environment, suitable for mass production. The disadvantage is that the one-off investment is high.
